Recently, as a display apparatus, a liquid crystal display (LCD) or a plasma display panel (PDP) is used. Differently from the PDP of a self-emitting type, the LCD essentially requires a separate backlight unit due to absence of self-emitting light emitting devices.
As light sources of the backlight unit used in the LCD, cold cathode fluorescent lamps (CCFLs) are widely used. However, the backlight unit using the CCFLs may consume a considerable amount of power because power is applied to the CCFLs at all times, exhibit a color reproduction rate of about 70% that of a CRT, and cause environmental pollution due to addition of mercury.
In order to solve these problems, research into a backlight unit using light emitting diodes (LEDs) has been underway.
If LEDs are used for the backlight unit, an LED array may be partially turned on/off and thus power consumption may be considerably reduced. Particularly, RGB LEDs exceed 100% of national television system committee (NTSC) color reproduction range specifications, thus providing a more vivid image to consumers.
However, the related backlight unit does not uniformly guide light, and thus hot spots and dark regions may be generated.